Running DOOM On Earbuds

January 27, 2026 by No comments

In 1993, DOOM was a great game to play if you had a 486 with a VGA monitor and nothing to do all weekend. In 2026, you can play it on a set of earbuds instead, if for some reason that’s something you’ve always dreamed of doing.

The project comes to us from [Arin Sarkisian], who figured out that the Pinebuds Pro had enough processing power to run one of the seminal FPS games from the 1990s. Inside these earbuds is a Cortex-M4F, which is set to run at 100 MHz. [Arin] figured out it could easily be cranked up to 300 MHz with low power mode switched off, which would come in handy for one main reason. See, the earbuds might be able to run the DOOM engine, but they don’t have a display.

Thus, [Arin] figured the easiest way to get the video data out would be via the Cortex-M4F’s serial UART running at 2.4 mbps. Running the game at a resolution of 320 x 200 at 3 frames per second would consume this entire bandwidth. However, all those extra clock cycles allow running an MJPEG compression algorithm that allow spitting out up to 18 frames per second. Much better!

All that was left to do was to figure out a control scheme. To that end, a web server is set up off-board that passes key presses to the buds and accepts and displays the MJPEG stream to the player. If you’re so inclined you can even play the game yourself on the project website, though you might just have to get in a queue. In the meantime, you can watch the Twitch stream of whoever else is playing at the time.

Files are on GitHub—both the earbud firmware and the web interface used to play the game. It was perhaps only a matter of time until we saw DOOM on earbuds; no surprise given that we’ve already seen it played on everything from receipt printers to cookware. No matter how cliche, we’re going to keep publishing interesting DOOM ports—so keep them coming to the tipsline.

Thanks to [alialiali] for the tip!

Zombie Netscape Won’t Die

January 27, 2026 by 2 Comments

The very concept of the web browser began with a humble piece of software called NCSA Mosaic, all the way back in 1993. It was soon eclipsed by Netscape Navigator, and later Internet Explorer, which became the titans of the 1990s browser market. In turn, they too would falter. Navigator’s dying corpse ended up feeding what would become Mozilla Firefox, and Internet Explorer later morphed into the unexceptional browser known as Edge.

Few of us have had any reason to think about Netscape Navigator since its demise in 2008. And yet, the name lingers on. A zombie from a forgotten age, risen again to haunt us today.

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Pi Compute Module Powers Fully Open Smartphone

January 27, 2026 by 11 Comments

With the powerful off-the-shelf hardware available to us common hardware hobbyist folk, how hard can it be to make a smartphone from scratch? Hence [V Electronics]’s Spirit smartphone project, with the video from a few months ago introducing the project.

As noted on the hardware overview page, everything about the project uses off the shelf parts and modules, except for the Raspberry Pi Compute Module 5 (CM5) carrier board. The LCD is a 5.5″, 1280×720 capacitive one currently, but this can be replaced with a compatible one later on, same as the camera and the CM5 board, with the latter swappable with any other CM5 or drop-in compatible solution.

The star of the show and the thing that puts the ‘phone’ in ‘smartphone’ is the Quectel EG25-GL LTE (4G) and GPS module which is also used in the still-not-very-open PinePhone. Although the design of the carrier board and the 3D printable enclosure are still somewhat in flux, the recent meeting notes show constant progress, raising the possibility that with perhaps some community effort this truly open hardware smartphone will become a reality.

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Two very similar diffraction patterns are shown, in patterns of green dots against a blue background. The left image is labelled "Kompressions-algorithmus", and the one on the right is labelled "Licht & Zweibelzellen".

Why Diffraction Gratings Create Fourier Transforms

January 27, 2026 by 6 Comments

When last we saw [xoreaxeax], he had built a lens-less optical microscope that deduced the structure of a sample by recording the diffraction patterns formed by shining a laser beam through it. At the time, he noted that the diffraction pattern was a frequency decomposition of the specimen’s features – in other terms, a Fourier transform. Now, he’s back with an explanation of why this is, deriving equations for the Fourier transform from the first principles of diffraction (German video, but with auto-translated English subtitles. Beware: what should be “Huygens principle” is variously translated as “squirrel principle,” “principle of hearing,” and “principle of the horn”).

The first assumption was that light is a wave that can be adequately represented by a sinusoidal function. For the sake of simplicity (you’ll have to take our word for this), the formula for a sine wave was converted to a complex number in exponential form. According to the Huygens principle, when light emerges from a point in the sample, it spreads out in spherical waves, and the wave at a given point can therefore be calculated simply as a function of distance. The principle of superposition means that whenever two waves pass through the same point, the amplitude at that point is the sum of the two. Extending this summation to all the various light sources emerging from the sample resulted in an infinite integral, which simplified to a particular form of the Fourier transform.

One surprising consequence of the relation is the JPEG representation of a micrograph of some onion cells. JPEG compression calculates the Fourier transform of an image and stores it as a series of sine-wave striped patterns. If one arranges tiles of these striped patterns according to stripe frequency and orientation, then shades each tile according to that pattern’s contribution to the final image, one gets a speckle pattern with a bright point in the center. This closely resembles the diffraction pattern created by shining a laser through those onion cells.

For the original experiment that generated these patterns, check out [xoreaxeax]’s original ptychographical microscope. Going in the opposite direction, researchers have also used physical structures to calculate Fourier transforms.

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The History Of Tandem Computers

January 26, 2026 by 5 Comments

If you are interested in historical big computers, you probably think of IBM, with maybe a little thought of Sperry Rand or, if you go smaller, HP, DEC, and companies like Data General. But you may not have heard of Tandem Computers unless you have dealt with systems where downtime was unacceptable. Printing bills or payroll checks can afford some downtime while you reboot or replace a bad board. But if your computer services ATM machines, cash registers, or a factory, that’s another type of operation altogether. That was where Tandem computers made their mark, and [Asianometry] recounts their history in a recent video that you can watch below.

When IBM was king, your best bet for having a computer running nonstop was to have more than one computer. But that’s pricey. Computers might have some redundancy, but it is difficult to avoid single points of failure. For example, if you have two computers with a single network connection and a single disk drive. Then failures in the network connection or the disk drive will take the system down.

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One Hundred Years Of Telly

January 26, 2026 by 6 Comments

Today marks an auspicious anniversary which might have passed us by had it not been for [Diamond Geezer], who reminds us that it’s a hundred years since the first public demonstration of television by John Logie Baird. In a room above what is today a rather famous Italian coffee shop in London’s Soho, he had assembled a complete mechanical TV system that he demonstrated to journalists.

Television is one of those inventions that owes its genesis to more than a single person, so while Baird was by no means the only one inventing in the field, he was the first to demonstrate a working system. With mechanical scanning and just 30 lines, it’s hardly HD or 4K, but it does have the advantage of being within the reach of the constructor.

Perhaps the saddest thing about Baird and his system is that while he was able to attract the interest of the BBC in it, when the time came for dedicated transmissions at a higher resolution, his by then partly mechanical system could not compete and he faded into relative obscurity. Brits instead received EMI’s 405 line system, which persisted until the very start of the 1980s, and eventually the German PAL colour system in the late 1960s.

So head on down to Bar Italia if you can to raise a coffee to his memory, and should you wish to have a go at Baird-style TV for yourself, then you may need to print yourself a disk.

Header image: Matt Brown, CC BY 2.0.

Create A Tiny Telephone Exchange With An Analog Telephone Adapter

January 26, 2026 by 11 Comments

An analog telephone adapter (ATA), or FXS gateway, is a device that allows traditional analog phones to be connected to a digital voice-over-IP (VoIP) network. In addition to this, you can even create a local phone exchange using just analog phones without connecting to a network as [Playful Technology] demonstrates in a recent video.

The ATA used in the video is the Grandstream HT802, which features one 10/100 Mbps Ethernet port and two RJ11 FXS ports for two POTS phones, allowing for two phones to be directly connected and configured using their own profiles.

By using a multi-FXS port ATA in this manner, you essentially can set up your own mini telephone exchange, with a long run of Cat-3 possible between an individual phone and the ATA. Use of the Ethernet port is necessary just once to configure the ATA, as demonstrated in the video. The IP address of the ATA is amusingly obtained by dialing *** on a connected phone and picking 02 as menu option after which a synthetic voice reads out the number. This IP address gets you into the administration interface.

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